Situated on the Euphrates river (picture, right, from McMath), which as a major river ensured permanent fertility.
Babylon was already a major center in the patriarchal period. It was firmly
part of the Assyrian empire in Amos' time. However in c. 612BC Babylon led a
successful revolt against the Assyrians and
so became the new center of Imperial power in the region.

Indirectly via Canaan and
later directly through the exile
Babylonian culture exercised a profound effect on the OT.